WO2023059291A1

WO2023059291A1 - Thermopile firebrick

Info

Publication number: WO2023059291A1
Application number: PCT/TR2022/051052
Authority: WO
Inventors: Omer KARA
Original assignee: Istanbul Teknik Universitesi ITU
Current assignee: Istanbul Teknik Universitesi ITU
Priority date: 2021-10-07
Filing date: 2022-09-28
Publication date: 2023-04-13
Anticipated expiration: 2024-04-07

Abstract

The invention is related to the production of electrical energy with the thermoelectric method by utilizing the waste heat released into the atmosphere through the exhaust gases from the chimneys in the industry, and to the production method of a thermopile firebrick that converts the leakage heat that occurs in heavy industry materials, mine processing facility chimneys such as iron-casting, and in places where there is intense heat into electricity.

Description

THERMOPILE FIREBRICK

Technical Field

Prior Art

Energy supply is among the primary problems of today’s world since the increasing human population also increases energy demand rapidly. This demand should be met with the same urgency. A large portion of the energy supply is provided traditionally, that is, with fossil fuels. However, this brings another considerable problem to our doorstep: Global warming. Scientists are making great endeavors to maintain the energy supply-demand balance and to provide energy supply with more environmentally friendly methods. New methods are being developed every day. Thermoelectric methods are among the methods that are open to development. It is possible to produce electricity by making use of waste heat sources as well as renewable energies such as solar energy in electricity production with the thermoelectric method.

In addition, the unused and discarded part of the energy and the damage it causes to our nature is surely the biggest problem. All processes that emit heat to the environment (waste heat) such as factory chimneys, engine surfaces, boiler rooms, steam pipe surfaces in factories, or the surfaces of the engine, exhaust pipe of the vehicles, heated mechanical parts, etc. harm the ecosystem and trigger global warming. In addition, as the efficiency decreases due to the energy discarded due to heating; the production life of metal, iron, casting, etc. materials on the heated surface decrease as well. As a solution in this field, refrigerant is circulated for heated surfaces, or insulation material is used. However, due to instantaneous heat transfers, these solution precautions remain insufficient. In addition, these measures constitute an extra financial burden. Mechanical parts that are heated due to instantaneous heat transfers also cause the machine that produces the heat to overheat after a while. An example is the overheating of vehicle engines due to heating. In addition, the hardware and circuits required for the refrigerant circulated in the interior of the heated surfaces cause bulky and unnecessary occupation of space, since they take up a large space.

Innovative designs that will enable the recycling of waste heat can be given as a solution. However, the most important problem here is the costs of the designs presented as the solution. The designs with the lowest energy unit recycling costs will surely be one of the best solution methods.

Various improvements have been made in the art regarding the recycling of waste heat.

In the Korean patent document numbered KR100994269B1 in the known state of the art, a negative electrode active material that exhibits a fine particle size and can be applied to an electrochemical device such as a lithium-ion or polymer secondary battery or similar, containing an oxide of calcium and cobalt as the main component is mentioned. In the said patent document, it is mentioned that the slurry obtained after certain chemical treatments is coated on a copper foil as a current collector and volatilized in a vacuum dryer kept at 100°C for 4 hours. In addition, in the related patent document, it is mentioned that an electrochemical device such as an electrochemical lithium ion or polymer secondary battery or similar, to which calcium-cobalt oxide based negative electrode active material is applied, can have a very high thermoelectric effect due to high conductivity and low thermal conductivity.

In the patent document number US5695824A in the known state of the art, coating material and a method for the coating that involves the coating of products such as incinerators, boilers, internal combustion engines, and firebricks, which are exposed to high temperatures with a solution or by painting them, thereby oxidizing them to certain extents and increasing their heat resistance are mentioned. This coating system refers to the coating of the outer part of the products. When the methods present in the art are examined, low-cost, environmentally friendly, and high-efficiency thermopile firebrick is not present. Therefore, there was a need to develop the method of the invention.

Objects of the Invention

The object of the present invention is to realize the production method of a thermopile firebrick that is low-cost, environmentally friendly, and highly efficient, and converts the waste heat released into the atmosphere into electrical energy with the thermoelectric method.

Another object of the present invention is to realize the production method of a thermopile firebrick that provides maximum benefit from the heat energy which is called entropy in the science of thermodynamics and lost in heating.

Detailed Description of the Invention

The thermopile firebrick realized to achieve the objects of the invention is shown in the attached figures.

In these figures;

Figure 1: Temperature-voltage experiment result graph with thermopile thermoelectric material

The invention is the thermopile firebrick production method, comprising the following steps

- obtaining Ca4Co3O9 composition with cobalt oxide (CO3O4) and calcium carbonate (CaCCh) and baking for 3-48 hours in an oven that is preheated to 650-1350°C, In addition to these materials, baking the Ca3Co4O9 and SrTiC compositions as well, shaping the baked composition by compressing the same with a hydraulic press and baking again for 3-48 hours at 650-1350°C,

- and obtaining the thermopile firebrick by placing the obtained product in a known firebrick. In the invention, the material baked at 1000°C is coated with steel alloy materials (masks) prepared previously under a high vacuum (1.5*10-³ - 9.5* 10-⁵). While a portion of the steel alloy materials is coated with (P-Type) CaCosCh, Ca3Co4O9, some of them are coated with (N-Type) SnCo4O9, SrTiCh, ZnAhCh, or CaMnCh materials. Then, the thermopile firebrick is obtained by placing it in a firebrick.

Preparation of the Ca4Co3C>9 Compound as a Chemical Material:

In the chemical composition used, the mass of the cobalt oxide (CO3O4) as one of the products in the chemical composition is (4 moles x 240.797 g/moles) 963.188 grams, and the mass of the calcium carbonate (CaCCh) is (9 moles x 100.087 g/moles) 900.783 grams. Approximately 0.963188 mg of cobalt oxide (CO3O4) and approximately 0.900783 mg of calcium carbonate (CaCCh) are weighed with a precision scale, cleaned, and stirred in an empty pot for 15 minutes until homogeneous. The pot is placed in an oven preheated to 1100°C for 24 hours to bake, and the Ca4Co3O9 composition is obtained (Equation I).

After being compressed with a hydraulic press, the baked material is shaped in certain dimensions. The shaped material is baked again at 1000°C for 24 hours, and in this way, the Thermo Pile module product is readied for making the design. Said product is placed in a known firebrick. Thereby, the production of thermopile firebrick is completed. In the last stage, the electricity recycling potential of this thermopile firebrick is determined. Apart from this production method, some parts of the material baked at 1000°C are coated with copper with the help of masks (steel alloy product) prepared previously under a high vacuum. Then, while a portion thereof is coated with (P-Type) Ca4Co3O9, some thereof is coated with (N- Type) Sr3Co4O9, SrTiCh, ZnAhCh, or CaMnCh materials, together with the produced chemical.

Thermopile Firebrick

Since the resulting thermopile firebrick is in standard firebrick sizes, it is an important advantage that it can be easily used in the usage areas of the firebrick with the plug-and-play logic. While it can be easily mounted on heated surfaces, it is possible to create large surfaces and produce even larger amounts of electrical energy, and it is possible to store the same in accumulators.

Experimental Stage

With the thermopile firebrick product, a thermoelectric battery design was also considered for small-scale factory chimneys. Unlike the thermopile firebrick, this design is applied directly to the chimney, resulting in an even more efficiency increase.

The product consists of two stainless steel 304 cylinders (Height 10 cm, diameter 4 cm, and height 10 cm, diameter 5 cm) being placed between metals in the form of N-type and P-type with the composition of Ca4Co3O9 obtained in the other production method. As in the other modules, 3 tips were taken from both cylinder metals. Finally, it was fixed with cement with a special heat-resistant mixture to make it a fixed piece. A thermocouple was placed so that the exhaust gas temperature of the chimney could be measured from the chimney inlet. By using a combustible gel inside the chimney, the exhaust gas temperature was obtained and both the temperature was measured and the electrical energy produced from the chimney waste heat was measured with the thermoelectric module.

Apart from the prototype, the necessary electrical cable components for the circuit assembly and an accumulator were used to store the produced electrical energy.

Table 1 - Experiment results of electrical voltage generation of thermopile firebrick

As can be seen from Table 4.1 and Figure 4.2, as the temperature increases, the electrical voltage value obtained or recycled from the thermopile firebrick increases as well. It should be noted that these results are obtained from only one firebrick. As it is known, as the surface areas increase in the processes, the results to be obtained will be more concrete and realistic. Thereby, as the surface area of the prototype model increases, the voltage value will increase in proportion to the same. Thereby, it can be easily calculated that the surface area of a factory chimney can generate how much voltage from how much heat.

It is possible to use the said thermopile firebrick and coating mask products in every process where waste heat or inert heat sources are present. It can be used in all parts such as factory chimneys, engine surfaces, boiler rooms, steam pipe surfaces, heated mechanical parts, etc. in factories that have waste heat. Instead of the insulation material on the surfaces of the steam pipes, at the parts where the insulation materials used for thermal insulation are present in the boiler room or the firebrick parts inside the boiler, all the heated surfaces of the factory chimneys, the heat on the engine surfaces or the outer surface of the engine that is close to the engine cylinder bed, all the heated surfaces of the mechanical parts can be coated with firebricks produced and the mechanism circuit is established therein or these are coated directly between the masks (steel alloy material) in the firebrick via chemical compound modeling and by establishing the mechanism model, the electrical power thus produced can be accumulated in the accumulator via cables. Thereby, the waste heat discharged from the chimney or all other heated surfaces to the environment (open air) is recycled.

The thermopile firebrick obtained as a result of the developed method can be used in the stone and fire brick parts of the bakery ovens that come into contact with the fire. Bread ovens can produce electricity while baking bread at the same time. Thereby a large energy consumption is benefited.

The thermopile firebrick can be used in the panel and body protection parts of space satellites. Space satellites are a costly system that is highly required by people. However, since these space satellites run out of energy after a certain period, they have to be thrown into space junk. There are many studies to prevent this. Thanks to the module produced with the invention, electrical power can be produced by placing the same on the wings (panels) of the space satellite. That is because the parts of the space satellite panels facing the sun are + 100°C, while the parts that do not face the sun are -100°C. By placing this on the panel parts, a contribution can be made to the energy production and the life of space satellites can be extended.

Thermopile firebrick can be used to recover waste heat in nuclear reactor cores. It can be used in aircraft turbines and on the inner surfaces of the exhaust body, where jet fuel is burned. By covering all the heated surfaces as a result of the power spent for the propulsion of the aircraft with the module produced, the waste heat thrown into the open atmosphere (environment) is recycled and converted back into electrical power. Thereby, by using the electrical power accumulated in the accumulator, savings from jet fuel consumption, which is quite expensive, can be achieved by using waste heat. In the same way, the launch process, which rises to high temperatures, is carried out for launching in space shuttles. Electrical power energy can be obtained by using the module produced for taking advantage of this high temperature.

Claims

CLAIMS The invention is the production method of a thermopile firebrick that converts the leakage-waste heat into electricity, characterized in that; it comprises the following steps obtaining Ca4Co3O9 composition with cobalt oxide (CO3O4) and calcium carbonate (CaCCh) and baking for 3-48 hours in an oven that is preheated to 650-1350°C, shaping the baked composition by compressing the same with a hydraulic press and baking in the oven again for 3-48 hours at 650-1350°C, and obtaining the thermopile firebrick by placing the obtained product in a known firebrick. Thermopile firebrick production method according to Claim 2, characterized in that; it comprises the following steps coating the composition baked at 1000°C with copper together with the preprepared steel alloy materials under 1.5*10-³ - 9.5* 10-⁵ vacuum, coating a portion of steel alloy materials with (P-Type) Ca4Co3O9, and coating another portion with (N-Type) Sr3Co4O9, SrTiCh, ZnAhCh, or CaMnCh materials, and obtaining the thermopile firebrick by placing the obtained product in a firebrick.

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